Finding suppliers in New Zealand isn't easy. I've been in the product sourcing game for a few years now (based in NZ), and have never used a New Zealand supplier; we just don't manufacturer a lot of stuff here.
Is the 5-8 day wait your only concern with buying from China? If so, I would say it is well worth the wait. You are much more likely to get products at better prices when importing from China.
A few other things you should know:
Electronics such as cameras and cell phones are pretty damn competitive on TradeMe. It's a market I myself would avoid. Unless you have some big money to invest (and therefore get a decent bulk-buying discount) you are likely to struggle against other more seasoned sellers who are selling the same products.
Also, when dealing with Chinese suppliers, know that 99% of the branded items that come out of China are fakes. With electronics, that can mean that the items don't function like the real thing does.
For example a camera might only have very little internal memory, or the external memory stick will be a bit fragile, so the user might lose some of their photos - not a good look if this appears in your feedback comments.
If you can track down a supplier in Hong Kong, however, you can be fairly sure that they will be selling authentic items, but expect large minimum orders when dealing with them.
I found a local cables supplier based in Christchurch that I quite like the look of:
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You might find that selling accessories like they offer will bring you much more success.